What is STP?

Spanning Tree Protocol (STP) is a network protocol that ensures a loop-free topology for Ethernet networks. In a local area network (LAN) with redundant links, loops can form, leading to broadcast storms, multiple frame copies, and instability in the network. STP eliminates these loops by selectively blocking certain paths, ensuring that there is always a single active path between network devices.

Understanding STP: Spanning Tree Protocol

In the world of networking, ensuring that data flows smoothly and efficiently is a top priority. One critical technology that supports this goal is the Spanning Tree Protocol (STP). Introduced by IEEE as part of the 802.1D standard, STP is essential for preventing loops in a network, which can otherwise cause significant disruptions.

How Does STP Work?

STP uses the following process to maintain a loop-free network:

Root Bridge Election:
The protocol selects a single switch to act as the root bridge. This decision is based on the switch with the lowest bridge ID, which is a combination of a priority value and the switch’s MAC address.
Path Selection:
STP calculates the shortest path from each switch to the root bridge. The cost of a path is determined by the bandwidth of the links. Higher bandwidth links have lower costs.
Port Roles:
Each port on a switch is assigned a role:
Root Port: The port with the shortest path to the root bridge.
Designated Port: The port on each segment that provides the shortest path to the root bridge.
Blocked Port: Any port not selected as a root or designated port is placed in a blocking state to prevent loops.
Types of STP

Over time, variations of STP have been developed to improve performance and adapt to modern networking needs:

One time auto switch theu STP .
Auto STP
Contineous & Regular STPs by re-filling .